Method and apparatus for scheduling assignment of uplink packet transmission in mobile telecommunication system

ABSTRACT

Methods and apparatus are provided for communication between a User Equipment (UE) and a Node B in a communication system. The UE generates a Media Access Control-Protocol Data Unit (MAC-PDU) including scheduling information having information representing an amount of packet data to be transmitted. The MAC-PDU including the scheduling information is transmitted to the Node B. The information representing the amount of packet data exists per priority queue.

PRIORITY

This application is a continuation of application Ser. No. 10/925,619,filed Aug. 25, 2004, the contents of which are incorporated herein byreference.

This application claims priority to an application entitled “Method AndApparatus For Scheduling Assignment Of Uplink Packet Transmission InMobile Telecommunication System” filed in the Korean IntellectualProperty Office on Aug. 26, 2003 and assigned Serial No.10-2003-0059172, the contents of which are hereby incorporated byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a mobile telecommunication system, andmore particularly to a method and an apparatus for efficientlytransceiving scheduling assignment information for transmitting packetdata through an uplink (UL).

2. Description of the Related Art

An asynchronous Wideband Code Division Multiple Access (hereinafter,referred to as a WCDMA) communication system employs an Enhanced UplinkDedicated Channel (hereinafter, referred to as an EUDCH or E-DCH) inorder to support a high speed packet data service through an uplink. TheEUDCH is a channel proposed to improve the performance of a packettransmission in an uplink communication in an asynchronous code divisionmultiple access communication system. The EUDCH-related technologyincludes new technologies for a more reduced Transmission Time Interval(TTI) together with the Adaptive Modulation and Coding (AMC) method andthe Hybrid Automatic Retransmission Request (HARM) method already usedin a High Speed Downlink packet access (HSDPA). Further, a Node Bcontrol scheduling of an uplink channel is used. The Node B controlscheduling for the uplink is very different from a scheduling for adownlink.

Since uplink signals transmitted from a plurality of user equipments(hereinafter, referred to as UEs) do not maintain orthogonality betweenthe uplink signals, the uplink signals function as interference signalsbetween themselves. Therefore, as the number of uplink signals receivedin the Node B increase, the number of interference signals for uplinksignals transmitted from a specific UE also increases. Accordingly, asthe number of the interference signals with respect to the uplinksignals transmitted from the specific UE increases, the receptionperformance of the Node B is reduced. In order to overcome such aproblem, uplink transmission power may be increased. However, an uplinksignal having increased transmission power also functions as aninterference signal with respect to another signal. Accordingly, theNode B limits the number of a receivable uplink signals while ensuringits own reception performance. Equation (1) represents the number of thereceivable uplink signal while the reception performance of the Node Bis ensured.

$\begin{matrix}{{R\; O\; T} = \frac{I_{o}}{N_{o}}} & (1)\end{matrix}$

In Equation (1), I_(o) represents an entire reception wideband powerspectral density of the Node B and N_(o) represents a thermal noisepower spectral density of the Node B. Accordingly, the ROT is a radioresource capable of being assigned by the Node B for the EUDCH packetdata service in an uplink.

FIGS. 1A and 1B show variations of an uplink radio resource assigned bya Node B. As shown in FIGS. 1A and 1B, the uplink radio resourceassigned by the Node B is obtained by the sum of inter-cell interference(hereinafter, referred to as an ICI), voice traffic, and EUDCH packettraffic.

FIG. 1A shows variation of the total ROT when Node B scheduling is notused. Since scheduling is not performed for the EUDCH packet traffic,the total ROT grows larger than a target ROT when a plurality of UEstransmit the packet data at a high data rate at the same time. Herein,the reception performance of the uplink signal is reduced.

FIG. 1B shows variation of the total ROT when Node B scheduling is used,thereby preventing the multiple UEs from transmitting the packet data ata high data rate at the same time. That is, the Node B schedulingenables a high data rate to be permitted to a specific UE and a low datarate to be permitted to other UEs, thereby preventing the total ROT fromexceeding the target ROT. Accordingly, Node B scheduling can alwaysmaintain constant reception performance.

The Node B notifies each UE of information regarding whether or notEUDCH data can be transmitted by means of a request data rate of UEsusing the EUDCH or channel status information representing transmissionquality of an uplink. Also, the Node B adjusts the EUDCH data rate.Further, in order to improve the performance of a mobile communicationsystem, the Node B scheduling assigns the data rate to the UEs so thatthe total ROT of the Node B does not exceed the target ROT. For example,the Node B may assign a low data rate to a UE in a position remote fromthe Node B and a high data rate to a UE in a position near to the NodeB.

FIG. 2 is a view illustrating a basic concept regarding circumstances inwhich a Node B scheduling is used in an EUDCH. In FIG. 2, Node B 200supports the EUDCH and reference numerals 210, 212, 214, and 216represent UEs transmitting the EUDCH. When a data rate of a certain UEincreases, reception power received in the Node B 200 from the UEincreases. Accordingly, a ROT of the UE occupies a large portion of thetotal ROT. In contrast, when a data rate of another UE is reduced,reception power received in the Node B 200 from another UE is reduced.Accordingly, a ROT of another UE occupies a small portion of the totalROT. The Node B 200 performs the Node B scheduling for the EUDCH packetdata in consideration of the relation between the data rates and a radioresource requested by the UEs 210, 212, 214, and 216.

In FIG. 2, the UEs 210, 212, 214, and 216 transmit the packet data withdifferent uplink transmission powers from each other according to thedistance between the Node B 200 and the UEs 210, 212, 214, and 216. UE210, in the furthest position from the Node B 200, transmits the packetdata with the highest transmission power 220 of an uplink channel. Incontrast, UE 214, in the nearest position to the Node B 200, transmitsthe packet data with the lowest transmission power 224 of an uplinkchannel. In order to improve the performance of a mobile communicationsystem while maintaining the total ROT and reducing an ICI for anothercell, the Node B performs scheduling so that the transmission powerintensity of the uplink channel is inversely proportional to the datarate, thereby assigning a relatively lower data rate to the UE 210having the highest transmission power of an uplink channel and arelatively higher data rate to the UE 214 having the lowest transmissionpower of an uplink channel.

FIG. 3 is a flow diagram illustrating a basic transmission/receptionprocedure between a UE 302 transmitting an EUDCH and a Node B 301including the UE 302.

In step 303, a setup of an EUDCH is accomplished between the Node B 301and the UE 302. The setup step includes a transmission step of messagesthrough a dedicated transport channel. When the EUDCH setup isaccomplished, the UE 302 informs the Node B 301 of schedulinginformation at step 304. The scheduling information may include UEtransmission power information enabling uplink channel information to beunderstood, extra information of transmission power capable of beingtransmitted by a UE, and the amount of data stored in a buffer of a UEthat must be transmitted.

In step 311, the Node B 301 monitors the scheduling information of theUE 302 and schedules the UE 302. When the Node B 301 determines topermit an uplink data transmission to the UE 302 in step 311, the Node B301 transmits scheduling assignment information containing an assigneddata rate and a transmission timing to the UE 302 in step 305. In step312, the UE 302 determines a Transport Format (TF) such as a data ratefor a EUDCH transmission based on the scheduling assignment informationand chooses a Transport Format Resource Indicator (TFRI) indicating theTF. In step 307, the UE 302 transmits EUDCH data by means of the TFRI.Further, the TFRI, which is related information representing the TF ofthe EUDCH data, is transmitted to the Node B 301 in step 306 togetherwith the EUDCH data. In step 313, the Node B 301 determines whether ornot an error exists in the TFRI and the EUDCH data. As a result of thedetermination, when the error exists in at least one of the TFRI and theEUDCH data, the Node B 301 transmits an NACK to the UE 302 through anACK/NACK channel, in step 308. In contrast, when any error does notexist in the TFRI and the EUDCH data, the Node B 301 transmits an ACK tothe UE 302 through an ACK/NACK channel, in step 308.

The Node B 301 decides a data rate to be assigned to a UE on the basisof the scheduling information. Herein, the Node B 301 assigns a properdata rate and transmission timing to multiple UEs using an EUDCH.Further, in the scheduling, the Node B 301 assigns a resource to each UEin order to prevent a ROT value of an uplink from exceeding a target ROTvalue. Herein, the Node B 301 assigns many resources to a UE having agood channel condition in order to improve the entire performance of asystem.

FIG. 4 is a view showing the types of data transmitted from a UE to aNode B for an uplink packet data service.

As shown in FIG. 4, a UE 400 can transmit voice and image traffic,packet data, data regarding a game, etc., to a Node B 402 through anEUDCH. The data transmitted from the UE as described above requiresdifferent quality of service (QoS) according to the types of the data.Accordingly, it is necessary to provide a method by which the Node B 402performs a scheduling and assigns a radio resource according to qualityof service required by data to be transmitted from a UE.

SUMMARY OF THE INVENTION

Accordingly, the present invention has been made to solve theabove-mentioned problems occurring in the prior art, and it is an objectof the present invention is to provide a method and an apparatus forassigning a radio resource according to quality of service required bydata to be transmitted.

It is another object of the present invention is to provide a method andan apparatus for assigning many radio resources with respect to datarequesting high quality of service and a few radio resources withrespect to data requesting low quality of service.

It is further object of the present invention is to provide a method andan apparatus for efficiently using a radio resource of a mobilecommunication system by assigning radio resources different from eachother according to quality of service.

In order to accomplish the aforementioned objects, according to oneaspect of the present invention, a method is provided for communicationbetween a UE and a Node B in a communication system. The UE generates aMedia Access Control-Protocol Data Unit (MAC-PDU) including schedulinginformation having information representing an amount of packet data tobe transmitted. The MAC-PDU including the scheduling information istransmitted to the Node B. The information representing the amount ofpacket data exists per priority queue.

In order to accomplish the aforementioned objects, according to anotheraspect of the present invention, An apparatus is provided forcommunication between a UE and a Node B in a communication system. Theapparatus includes a data unit generator for generating a MAC-PDUincluding scheduling information having information representing anamount of packet data. The apparatus also includes a transmission unitfor transmitting the MAC-PDU including the scheduling information to theNode B. The information representing the amount of packet data existsper priority queue.

In order to accomplish the aforementioned objects, according to afurther aspect of the present invention, a method is provided forcommunication between a UE and Node B in a communication system. TheNode B receives a MAC-PDU including scheduling information havinginformation representing an amount of packet data to be transmitted fromthe UE. The scheduling information is detected from the MAC-PDU. Anuplink packet data service of the UE is scheduled based on thescheduling information. The information representing the amount ofpacket data exist per priority queue of the UE.

In order to accomplish the aforementioned objects, according to stillanother aspect of the present invention, an apparatus for communicationbetween a UE and a Node B in a communication system. The apparatusincludes a reception unit for receiving a MAC-PDU including schedulinginformation having information representing an amount of packet data tobe transmitted from the UE. The apparatus also includes a detection unitfor detecting the scheduling information from the MAC-PDU. The apparatusfurther includes a scheduler for scheduling an uplink packet dataservice of the UE based on the scheduling information. The informationrepresenting the amount of packet data exist per priority queue of theUE.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentinvention will be more apparent from the following detailed descriptiontaken in conjunction with the accompanying drawings, in which:

FIG. 1A is a view showing variations of an uplink radio resource of aNode B when a Node B control scheduling is not used;

FIG. 1B is a view showing variations of an uplink radio resource of aNode B when a Node B control scheduling is used;

FIG. 2 is a view illustrating a UE and a Node B performing uplink packettransmission;

FIG. 3 is a view showing information exchanged between a UE and a Node Bin order to perform uplink packet transmission;

FIG. 4 is a view showing the types of data transmitted from a UE to aNode B for an uplink packet data service;

FIG. 5 is a view showing a structure of a logical layer of a UEaccording to a preferred embodiment of the present invention;

FIG. 6 is a view illustrating transmission/reception of schedulingassignment information between a UE and a Node B according to oneembodiment of the present invention;

FIG. 7 is a view illustrating transmission/reception of schedulingassignment information between a UE and a Node B according to anotherembodiment of the present invention;

FIG. 8 is a view showing a structure of a logical layer of a UEaccording to a preferred embodiment of the present invention;

FIG. 9 is a flowchart illustrating an operation performed in a structureof a logical layer of a UE according to a preferred embodiment of thepresent invention;

FIG. 10 is a view illustrating an operation by which buffer statusinformation is transmitted from a logical layer of a UE to a logicallayer of a Node B according to a preferred embodiment of the presentinvention;

FIG. 11 is a view showing a structure of an EUDCH transmitting a bufferstatus information of a UE according to a preferred embodiment of thepresent invention;

FIG. 12 is a view showing a structure of a logical layer of a Node Baccording to a preferred embodiment of the present invention;

FIG. 13 is a flowchart showing an operation performed in a structure ofa logical layer of a Node B according to a preferred embodiment of thepresent invention;

FIG. 14 is a block diagram illustrating a transmission/receptionoperation performed by a UE according to a preferred embodiment of thepresent invention; and

FIG. 15 is a block diagram illustrating a transmission/receptionoperation performed by a Node B according to a preferred embodiment ofthe present invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE PRESENT INVENTION

Hereinafter, a preferred embodiment according to the present inventionwill be described with reference to the accompanying drawings. In thefollowing description of the present invention, a detailed descriptionof known functions and configurations incorporated herein will beomitted when it may make the subject matter of the present inventionunclear.

A Universal Mobile Telecommunication Service (hereinafter, referred toas a UMTS), one of the 3^(rd) Generation Partnership Project (3GPP)mobile communication services, is based on a communication standard of aGlobal System for Mobile Communication (hereinafter, referred to as aGSM) and a General Packet Radio Service (GPRS) employs a wideband CDMAtechnology, in contrast to the GSM employing a Time Division MultipleAccess (TDMA). A UMTS Terrestrial Radio Access Network (hereinafter,referred to as a UTRAN) includes Node Bs containing a plurality of cellsand a Radio Network Controller (hereinafter, referred to as a RNC)managing radio resources of the Node Bs.

An interface between a UE and a RNC is called an Uu interface and isclassified as a control plane for exchanging control and signalingsignals and a user plane for transmitting data traffic. The controlplane includes a radio resource control (RRC) layer, a radio linkcontrol (RLC) layer, a media access control (MAC) layer, and a physical(hereinafter, referred to as a PHY) layer. Further, the user planeincludes a packet data control protocol (PDCP) layer, an RLC layer, aMAC layer, and a PHY layer. Herein, the PHY layer is located in eachcell and the layers between a MAC layer and a RRC layer are located in aRNC.

Particularly, a portion related to a user plane in a MAC layer is calleda MAC-d and a portion related to a control plane is called a MAC-c. Userdata to be transmitted through a dedicated transport channel isgenerated into a transmission block having a desired size through aMAC-d layer. When the user data is transmitted through an EUDCH, thetransmission block passes through a MAC-eu portion in the MAC layer. AMAC-eu layer performs a process a Node B control scheduling, HARQ, etc.,for an EUDCH before transmitting data sent from a MAC-d layer to a PHYlayer.

FIG. 5 is a view showing a structure of a MAC-eu layer of a UEtransmitting an EUDCH according to a preferred embodiment of the presentinvention.

The MAC-eu layer 500 of the UE includes a priority queue distributor 502and a priority queues (PQs) 504, and receives data to be transmitted toa Node B from a MAC-d layer 518. The received data is sent to thepriority queue distributor 502 of the MAC-eu layer 500. The priorityqueue distributor 502 determines a priority for the received data andbuffers the data in a priority queue, which corresponds to thedetermined priority, from among the priority queues 504.

The priority queues 504 are used in storing data according to a priorityof a service to be provided and have inherent queue identifiers(hereinafter, referred to as QIDs) respectively. That is, each of thepriority queues 504 is related to at least one service and stores datahaving different priorities. FIG. 5 shows two priority queues 504, butthe number of the priority queues 504 is randomly determined by a MACcontrol signal 516 according to the type and number of services beingprovided. That is, when a priority for data to be transmitted to theNode B is classified as multiple steps, the number of the priorityqueues 504 increases. The priority is determined according to atransmission time point (i.e., required delay) at which data is to betransmitted to the Node B. That is, data which must be transmitted tothe Node B within a rapid time period has a high priority, and datawhich does not have the necessity of being transmitted to the Node Bwithin a rapid time period has a low priority.

The priority queue distributor 502 determines a priority for thereceived data and sends the data to one of the priority queues 504according to the determined priority. In this way, data having the samepriority is sent to the same priority queue. The priority queues 504store the received data before a resource is assigned by the schedulingof the Node B.

In order to request a scheduling assignment from the Node B, the MAC-eulayer 500 transmits scheduling information, which contain a bufferstatus representing the amount of the data stored in the priority queues504 and a channel status representing the transmission quality of anuplink, through an EUDCH related uplink 510. When the Node B transmitsscheduling assignment information to the UE through an EUDCH relateddownlink 514, a Transport format combination (hereinafter, referred toas a TFC) selection part 508 determines a TFC by means of the schedulingassignment information, reads the data from the priority queues 504 bymeans of the determined TFC, and transmits the read data through anEUDCH 512. Herein, the UE first transmits data having a high prioritystored in the priority queues 504. Therefore, a transmission time can bedifferently designated according to the priority. Meanwhile, an HARQentity 506 interprets an ACK/NACK received through the related downlink514 with respect to the transmitted data, discards data stored in acorresponding priority queue when an ACK is received, and retransmitsdata stored in a corresponding priority queue when an NACK is received.

FIG. 6 is a view illustrating an operation by which two UEs requesta_scheduling assignment to a Node B according to one embodiment of thepresent invention.

In FIG. 6, the UE 610 includes two priority queues 612 and 614 and theUE 620 includes one priority queue 622. The priority queue 612 of the UE610 has a priority higher than that of the priority queue 614, and thepriority queue 622 of the UE 620 has the same priority as that of thepriority queue 612 of the UE 610. The priority queue 612 of the UE 610stores 100 bits of data, the priority queue 614 of the UE 610 stores 300bits of data, and the priority queue 622 of the UE 620 stores 300 bitsof data. The Node B 600 has a radio resource capable of receiving only450 bits of data.

Referring to FIG. 6, the UEs 610 and 620 transmit buffer statusinformation 630 and 632 representing the amount of data to betransmitted to the Node B 600. That is, the UE 610 transmits the bufferstatus information 630 corresponding to 400 bits to the Node B 600, andthe UE 620 transmits the buffer status information 632 corresponding to300 bits to the Node B 600. Herein, when uplink channel conditions ofthe UEs 610 and 620 are identical to each other, the Node B 600transmits scheduling assignment information 640, which enables only 200bits to be transmitted, to the UE 610, and scheduling assignmentinformation 642, which enables only 150 bits to be transmitted, to theUE 620.

The UE 610 determines a TFC by means of the scheduling assignmentinformation 640, transmits data through an EUDCH by means of thedetermined TFC. That is, according to a priority, 100 bits of data onstandby in the priority queue 612 are first transmitted, and then 100bits of data on standby in the priority queue 614 are transmitted. TheUE 620 also determines a TFC by means of the scheduling assignmentinformation 642, transmits data through an EUDCH by means of thedetermined TFC. That is, 150 bits of data on standby in the priorityqueue 622 are transmitted.

Herein, although the priority queue 612 of the UE 620 has a priorityhigher than that of the priority queue 614 of the UE 610, all data inthe standby state are not transmitted. That is, when there exists one UErequesting the scheduling assignment information to the Node B 600, datain the standby state are transmitted according to priority. However,when there exists two or more UEs requesting the scheduling assignmentinformation to the Node B 600, there occurs a problem in that datahaving a higher priority are transmitted later than data having a lowpriority.

FIG. 7 is a view illustrating a preferred embodiment of the presentinvention for solving the problem in FIG. 6. In FIG. 7, UEs 710 and 720transmit not only the amount of data but also information on a priorityto a Node B 700 at the same time.

Referring to FIG. 7, the UE 710 includes two priority queues 712 and 714and the UE 720 includes one priority queue 722. The priority queue 712of the UE 710 has a priority higher than that of the priority queue 714,and the priority queue 722 of the UE 720 has the same priority as thatof the priority queue 712 of the UE 710. The priority queue 712 of theUE 710 stores 100 bits of data, the priority queue 714 of the UE 710stores 300 bits of data, and the priority queue 722 of the UE 720 stores300 bits of data.

The UEs 710 and 720 transmit buffer status information 730 and 732containing the amount of data to be transmitted and information on apriority to the Node B 700. That is, the UE 710 transmits the bufferstatus information 730 containing the amount of data corresponding to400 bits and a QID representing a priority to the Node B 700. That is,the buffer status information 730 signifies that the amount of datacorresponding to a Priority 1 is 100 bits and the amount of datacorresponding to a Priority 2 is 300 bits. Further, the UE 720 transmitthe buffer status information 732 containing the amount of datacorresponding to 300 bits and a QID representing a priority to the NodeB 700. Herein, when uplink channel conditions of the UEs 710 and 720 areidentical to each other, the Node B 700 transmits scheduling assignmentinformation 740 and 742 to the UEs 710 and 720 in consideration of thepriority. That is, the Node B 700 transmits scheduling assignmentinformation 740, which enables only 100 bits to be transmitted, to theUE 710, and scheduling assignment information 742, which enables only250 bits to be transmitted, to the UE 720.

The UE 710 determines a TFC by means of the scheduling assignmentinformation 740, transmits data through an EUDCH by means of thedetermined TFC. That is, 100 bits of data on standby in the priorityqueue 712 are transmitted according to priority. The UE 720 alsodetermines a TFC by means of the scheduling assignment information 742,transmits data through an EUDCH by means of the determined TFC. That is,250 bits of data on standby in the priority queue 722 are transmitted.In this way, the UEs 710 and 720 can first transmit data having a highpriority.

FIG. 8 is a view showing a structure of a MAC-eu scheduling controllerof a UE according to a preferred embodiment of the present invention.

Referring to FIG. 8, the scheduling controller 800 includes aconfiguration controller 804, a priority queue (PQ) controller 802, anda TFC selector 806. The priority queue controller 802 receives bufferpayload information 810 and 812 from priority queues, and the bufferpayload information 810 and 812 represent the amount of data on standbyin each priority queue. In FIG. 8, it is assumed that N number ofpriority queues exist. The buffer payload information 810 representsbuffer payload information sent from a priority queue 1 and the bufferpayload information 812 represents buffer payload information sent froma priority queue n. Further, the priority queue controller 802 receivesqueue information 814 from the configuration controller 804. Herein, thequeue information 814 is configuration information of priority queues,and it is related to the sizes and the number of memories of priorityqueues.

The priority queue controller 802 transmits a buffer status information826 containing a QID regarding a priority of a corresponding bufferpayload information 810 and 812 to the Node B through an EUDCH tx part828.

The TFC selector 806 receives scheduling assignment information 820through a shared control channel for EUDCH (E-SCCH), a buffer statusinformation 816 about priority queues from the priority queue controller802, and scheduling configuration information from the configurationcontroller 804. The scheduling configuration information containspriorities of priority queues, transport format combination set, etc.The TFC selector 806 determines a TFC by means of the buffer statusinformation 816 and the scheduling assignment information 820. The TFCis determined so that data stored in a priority queue having a highpriority is first transmitted.

The TFC selector 806 transmits the determined TFC to a dedicatedphysical data channel for EUDCH (hereinafter, referred to as a E-DPDCH)tx part 824. The E-DPDCH tx part 824 transmits EUDCH packet data bymeans of the received TFC. Herein, the determined TFC is transmitted toa dedicated physical control channel for EUDCH (hereinafter, referred toas a E-DPCCH) tx part 822. The E-DPCCH tx part 822 transmits controlinformation containing the TFC together with the EUDCH packet data atthe same time point. Also, the TFC is transmitted to the priority queuecontroller 802 over a scheduling information 818. The priority queuecontroller 802 understands by means of the TFC the priority queue inwhich transmitted data has been in a standby state by means of the TFC,and renews the buffer status of the priority queues.

FIG. 9 is a flowchart illustrating an operation of a MAC-eu schedulingcontroller according to a preferred embodiment of the present invention.

Referring to FIG. 9, in step 900, the scheduling controller determineswhether or not new data has arrived at priority queues by buffer payloadinformation sent from priority queues. Further, the schedulingcontroller determines a priority queue from which the buffer payloadinformation has been transmitted, thereby understanding the amount andpriority of data transmitted to the priority queues. When the new datahas arrived at the priority queues, step 902 is performed. In contrast,when the new data has not arrived at the priority queues, the processreturns to step 900.

In step 902, the scheduling controller transmits buffer statusinformation containing the buffer payload information and buffer statusinformation containing a QID representing a priority relating to thebuffer payload information to a Node B.

In step 904, the scheduling controller determines whether or notscheduling assignment information is received from the Node B. Thescheduling assignment information contains information on a maximum datarate capable of being used by a UE and a permission timing. From theresult of the determination, when the scheduling assignment informationhas been received from the Node B, step 906 is performed. In contrast,when the scheduling assignment information has not been received fromthe Node B, the process returns to step 904.

In step 906, the scheduling controller determines a TFC within a datarate assigned by the scheduling assignment information. In determiningthe TFC, the scheduling controller enables data having a high priorityto be first transmitted in consideration of the priority of the datatransmitted to the priority queues. In step 908, the schedulingcontroller controls the data transmitted to the priority queues to betransmitted by means of the determined TFC. The MAC-eu layer generates aMAC-eu protocol data unit (PDU) containing data read from acorresponding priority queue by the control command of the schedulingcontroller, and transmits the generated MAC-eu PDU through the E-DPDCH.Further, the scheduling controller transmits the determined TFC throughthe E-DPCCH, and renews information on the changed buffer status. Therenewed buffer status is transmitted through an EUDCH.

FIG. 10 is a view illustrating a MAC-eu signaling between a UE and aNode B according to a preferred embodiment of the present invention. Asshown in FIG. 10, the MAC-eu layer 1000 of the UE transmits a bufferstatus message to the MAC-eu layer 1002 of the Node B. The buffer statusinformation contains a QID and a buffer payload of a priority queue asdescribed above.

FIG. 11 is a view showing a construction of a MAC-eu PDU containingbuffer status information according to a preferred embodiment of thepresent invention. As shown in FIG. 11, the MAC-eu PDU includes a MAC-euheader 1100 contained in a header part and a plurality of MAC-eu servicedata units 1102 (SDUs) contained in a payload part. Informationcontained in the MAC-eu header 1100 is as follows:

A version flag (VF) representing the version of a MAC-eu PDU format.

A QID identifying of a priority queue from which a MAC-eu SDU isoutputted, constructed of 3 bits.

A transmission sequence number (TSN) for realigning a MAC-eu SDUaccording to a priority, constructed of 5 to 6 bits.

An SID_k representing the size of MAC-d SDUs belonging to an x^(th)MAC-eu SDU set from among the sets of the MAC-d SDUs constituting aMAC-eu PDU, constructed of 2 to 3 bits.

An N_k representing the number of MAC-d PDUs belonging to a MAC-eu SDUset, constructed of 7 bits.

A flag (F). When flag (F) is set to 1, the next field is a MAC-eu PDU.When F (flag) is set to 0, the next field is an SID.

A QID map representing an identifier of a priority queue in which dataexists, and a bit number is assigned for as many as the number ofpriority queues. A numeral 1 represents existence of data and a numeral0 represents absence of data.

A buffer payload represents the size of data stored in priority queuesin which the value of the QID map is 1, and a bit number according tothe length of the QID map is assigned.

FIG. 12 is a view showing a structure of a MAC-eu scheduler of a Node Baccording to a preferred embodiment of the present invention.

Referring to FIG. 12, the scheduler 1200 includes a UE status analyzer1202 and a resource controller 1204. The UE status analyzer 1202receives buffer status messages and channel status messages 1210, 1212,and 1214 of UEs UE#1 to UE#N located in a cell area managed by the NodeB. The UE status analyzer 1202 receives buffer status informationaccording to a priority queue contained in a MAC-eu header of a MAC-euPDU transmitted from each UE and estimates the amount of data stored ina priority queue of each UE. Further, the UE status analyzer 1202transmits an estimated value for the amount of data in each UE to theresource controller 1204.

The resource controller 1204 calculates an ROT to be assigned to aspecific UE in consideration of the estimated value for the amount ofdata in each UE, the channel status, and a target ROT provided from anRNC through a Node B application protocol (NBAP), and determines amaximum allowed data rate to be assigned to the UE in consideration ofthe priorities of the priority queues of the UE. Further, when the TFCis determined, the size of data which can be transmitted from the UE andan offset of transmission power are determined according to the TFC. Themaximum allowed data rate to be assigned to the UE is contained inmaximum allowed TFC information 1220 and 1222 and then transmitted tothe UE by E-SCCH tx parts 1224 and 1226.

FIG. 13 is a flowchart showing an operation of a MAC-eu scheduler of aNode B according to a preferred embodiment of the present invention.

Referring to FIG. 13, in step 1300, the scheduler determines whether ornot a MAC-eu PDU containing scheduling information has been receivedfrom a UE. The scheduling information contains buffer payloadinformation of each UE and information on a priority of each buffer.From the result of the determination, when the scheduling informationhas been received, step 1302 is performed. In contrast, when thescheduling information has not been received, the process returns tostep 1300.

In step 1302, the scheduler determines a maximum allowed data rate to beassigned to the UE on the basis of the buffer status information and thechannel status information received from the UE. The maximum alloweddata rate is determined in consideration of the target ROT provided fromthe RNC and a priority of data to be transmitted by the UE. Further, themaximum allowed data rate is transmitted to the UE through a controlchannel relating to an EUDCH in step 1304.

FIG. 14 is a block diagram illustrating an apparatus for performing atransmission/reception operation by a UE according to a preferredembodiment of the present invention. First, an operation of a receptionside receiving scheduling assignment information will be described.

Referring to FIG. 14, a signal received in an antenna passes through aradio frequency (RF) unit 1442, is converted into a baseband signal, andthen is inputted to a descrambler 1400. The descrambler 1400 descramblesthe baseband signal by a scrambling code S_(dl,n). The descrambledsignal is sent to a despreader 1402. In order to performdechannelization for the descrambled signal, the despreader 1402multiplies the descrambled signal by a channelization code C_(es), andsends the dechannelized signal to a demodulation unit 1404. Thedechannelized signal is demodulated by the demodulation unit 1404 anddecoded by a decoding unit 1406. Then, an E-SCCH detection unit 1408detects the scheduling assignment information from the decoded signal,and the scheduling assignment information contains maximum allowed TFCinformation 1410 assigned to the UE.

The maximum allowed TFC information 1410 is transmitted to a MAC-euscheduling controller 1412 and the MAC-eu scheduling controller 1412determines a TFC by means of the maximum allowed TFC information 1410.The TFC is determined considering information on a priority of data onstandby in priority queues 1422 and 1424. For this reason, the priorityqueues 1422 and 1424 store data relating to one or more services havingdifferent priorities, and transmit a QID and buffer payload informationto the MAC-eu scheduling controller 1412 periodically or whenever newdata is stored. The MAC-eu scheduling controller 1412 transmitsinformation on the determined TFC to an E-DPCCH generator 1414. TheE-DPCCH generator 1414 generates a control signal containing othercontrol information and the TFC. The generated control signal is codedby a coding unit 1416 and the coded signal is modulated by a modulationunit 1418. Then, the modulated signal is subjected to channelization bya spreader 1420 with a channelization code Cec and then is transmittedto a multiplexer 1438.

A MAC-eu PDU generator 1428 performs two functions. First, the MAC-euPDU generator 1428 includes the QID and the buffer status informationsent from the MAC-eu scheduling controller 1412 into a MAC-eu header.Secondly, the MAC-eu PDU generator 1428 appends the MAC-eu header to thedata on standby in the priority queues 1422 and 1424 by means of the TFCsent from the MAC-eu scheduling controller 1412, and generates a MAC-euPDU. The MAC-eu PDU is coded by a coding unit 1430 and rate-matched by arate matching unit 1432. The rate-matched signal is modulated by amodulation unit 1434 and the modulated signal is subjected tochannelization by a spreader 1436 with a channelization code C_(e). Thechannel coded data is transmitted to multiplexer 1438. The multiplexer1438 multiplexes signals provided from the spreaders 1420 and 1436 andsignals from other channels. The multiplexed signal is scrambled by ascrambler 1440 with a scrambling code S_(dpch,n) and is converted intoan RF signal by an RF unit 1444. Then, the RF signal is transmitted tothe Node B through an antenna.

FIG. 15 is a block diagram illustrating an apparatus for performing atransmission/reception operation by a Node B according to a preferredembodiment of the present invention. First, an operation of a receptionside receiving scheduling information will be described. The receptionpart of the Node B has N number of reception paths 1540 and 1542corresponding to each of N number of UEs performing an uplink packetdata service. Herein, an operation of the reception path 1540corresponding to a UE#1 will be described, but it is apparent to thosewho skilled in the art that the other reception paths also perform thesame operations.

Referring to FIG. 15, a signal received in an antenna passes through anRF unit 1538, is converted into a baseband signal, and then is inputtedto a descrambler 1518. The descrambler 1518 descrambles the basebandsignal by a scrambling code S_(dpch,n). The descrambled signal is sentto despreaders 1520 and 1522 and then is dechannelized into an E-DPCCHsignal and an E-DPDCH signal. The E-DPCCH signal for whichchannelization has been performed by the despreader 1522 with achannelization code C_(ec) is demodulated by a demodulation unit 1524,and then is decoded by a decoding unit 1526. A control informationdetector 1527 detects control information necessary in receiving EUDCHdata from data decoded by the decoding unit 1526, and the controlinformation contains modulation information, etc., of the EUDCH data.

The E-DPDCH signal for which channelization has been performed by thedespreader 1520 with a channelization code C_(e) is demodulated by ademodulation unit 1528 with the modulation information detected by thecontrol information detection unit 1527. The demodulated signal issubjected to a rate-dematching by a rate-dematching unit 1530 and thenis decoded by a decoding unit 1532.

A MAC-eu header detection unit 1534 separates buffer status informationin a header and data in a payload from a MAC-eu PDU sent from thedecoding unit 1532. Herein, when a QID map in a MAC-eu header has valuesother than 0, the MAC-eu header detection unit 1534 detects bufferstatus information 1516 contained in the MAC-eu header to transmit thedetected buffer status information 1516 to a MAC-eu scheduler 1514.Herein, the buffer status information 1516 includes at least one QID andbuffer payload information. Further, the MAC-eu header detection unit1534 separates MAC-eu SDUs, except for the MAC-eu header, from theMAC-eu PDU and transmits the MAC-eu SDUs to reordering buffers of anupper layer. The reordering buffers are located in an RNC, correspond topriority queues of a UE-side, and align received MAC-eu SDUs accordingto TSNs of the MAC-eu SDUs.

The MAC-eu scheduler 1514 generates a maximum allowed TFC information1512 for each UE by means of the buffer status information 1516 andother scheduling information, and transmits the generated maximumallowed TFC information 1512 to an E-SCCH generator 1510. The maximumallowed TFC is determined considering a priority of data contained thebuffer status information to be transmitted. The E-SCCH generator 1510generates scheduling assignment information for the maximum allowed TFCinformation 1512. The scheduling assignment information is coded by acoding unit 1508 and then is modulated by a modulation unit 1506. Thesignal modulated by the modulation unit 1506 is subjected tochannelization by a spreader 1504 with a channelization code C_(es), andthen is transmitted to a multiplexer 1502. The multiplexer 1502multiplexes the received signal together with other downlink channelsignals. The multiplexed signal is scrambled by a scrambler 1500 with ascrambling code S_(dl,n) and is converted into an RF signal by an RFunit 1536. Then, the RF signal is transmitted to a UE through anantenna. As described above, in the present invention, when a UEtransmits data having required different priorities through an enhanceduplink channel at the same time, a Node B control scheduling reflectsthe priorities of the data. For this, the UE transmits buffer statusinformation of a priority queue corresponding to quality of service, anda Node B can perform scheduling by means of the received buffer statusinformation of the priority queue. Accordingly, the present inventionprovides a differentiated service according to required priorities,thereby satisfying the requirements of users.

While the invention has been shown and described with reference tocertain preferred embodiments thereof, it will be understood by thoseskilled in the art that various changes in form and details may be madetherein without departing from the spirit and scope of the invention asdefined by the appended claims.

1. A method for communication between a User Equipment (UE) and a Node Bin a communication system, the method comprising the steps of:generating, by the UE, a Media Access Control-Protocol Data Unit(MAC-PDU) comprising scheduling information having informationrepresenting an amount of packet data to be transmitted; andtransmitting the MAC-PDU comprising the scheduling information to theNode B, wherein the information representing the amount of packet dataexists per priority queue.
 2. The method as claimed in claim 1, whereinthe scheduling information is placed in the MAC-PDU before any MACService Data Unit (SDU).
 3. The method as claimed in claim 1, wherein ifa plurality of information representing an amount of packet data existin the scheduling information, the plurality of information are arrangedaccording to an order of priority queue ID.
 4. The method as claimed inclaim 1, wherein the scheduling information further comprises at leastone information representing at least one priority queue ID.
 5. Themethod as claimed in claim 4, wherein the at least one priority queue IDis placed before any information representing the amount of packet datain the scheduling information.
 6. The method as claimed in claim 1,wherein the scheduling information further comprises channel statusinformation representing a transmission power of the UE.
 7. The methodas claimed in claim 1, wherein the MAC-PDU further comprises a MAC-SDU.8. The method as claimed in claim 1, further comprising: receiving agrant relating to scheduling an assignment of an uplink packet dataservice from the Node B; determining the amount of packet data to betransmitted from each priority queue in a current transmission timebased on the grant; and generating the MAC-PDU based on the amount ofpacket data to be transmitted from each of priority queue andtransmitting the MAC-PDU based on the grant.
 9. The method as claimed inclaim 8, wherein the amount of data to be transmitted from each ofpriority queue is determined with reference to a Transport FormatCombination (TFC) determined according to the grant.
 10. The method asclaimed in claim 1, wherein the priority queue is defined in accordancewith a kind of service.
 11. An apparatus for communication between aUser Equipment (UE) and a Node B in a communication system, theapparatus comprising: a data unit generator for generating a MediaAccess Control-Protocol Data Unit (MAC-PDU) comprising schedulinginformation having information representing an amount of packet data;and a transmission unit for transmitting the MAC-PDU comprising thescheduling information to the Node B, wherein the informationrepresenting the amount of packet data exists per priority queue. 12.The apparatus as claimed in claim 11, wherein the scheduling informationis placed in the MAC-PDU before any MAC Service Data Unit (SDU).
 13. Theapparatus as claimed in claim 11, wherein if a plurality of informationrepresenting the amount of packet data exists in the schedulinginformation, the plurality of information is arranged according to anorder of priority queue ID.
 14. The apparatus as claimed in claim 11,wherein the scheduling information further comprises at least oneinformation representing at least one priority queue ID.
 15. Theapparatus as claimed in claim 14, wherein the at least one priorityqueue ID is placed before any information representing the amount ofpacket data in the scheduling information.
 16. The apparatus as claimedin claim 11, wherein the scheduling information further compriseschannel status information representing a transmission power of the UE.17. The apparatus as claimed in claim 11, wherein the MAC-PDU furthercomprises a MAC-SDU.
 18. The apparatus as claimed in claim 11, whereinthe scheduling controller receives a grant relating to scheduling anassignment of an uplink packet data service from the Node B, anddetermines the amount of packet data to be transmitted from eachpriority queue in a current transmission time based on the grant,wherein the MAC-PDU generator generates the MAC-PDU based on the amountof packet data to be transmitted from each priority queue, and thetransmission unit transmits the MAC-PDU based on the grant.
 19. Theapparatus as claimed in claim 18, wherein the amount of data to betransmitted from each priority queue is determined with reference to aTransport Format Combination (TFC) determined according to the grant.20. The apparatus as claimed in claim 11, wherein the priority queue isdefined in accordance with a kind of service.
 21. A method forcommunication between a User Equipment (UE) and Node B in acommunication system, the method comprising the steps of: receiving, bythe Node B, a Media Access Control-Protocol Data Unit (MAC-PDU)comprising scheduling information having information representing anamount of packet data to be transmitted from the UE; detecting thescheduling information from the MAC-PDU; and scheduling an uplink packetdata service of the UE based on the scheduling information, wherein theinformation representing the amount of packet data exist per priorityqueue of the UE.
 22. The method as claimed in claim 21, wherein thescheduling information is placed in the MAC-PDU before any MAC ServiceData Unit (SDU).
 23. The method as claimed in claim 21, wherein if aplurality of information representing the amount of packet data existsin the scheduling information, the plurality of information is arrangedaccording to an order of priority queue ID.
 24. The method as claimed inclaim 21, wherein the scheduling information further comprises at leastone information representing at least one priority queue ID.
 25. Themethod as claimed in claim 24, wherein the at least one priority queueID is placed before any information representing the amount of packetdata in the scheduling information.
 26. The method as claimed in claim21, wherein the scheduling information further comprises channel statusinformation representing a transmission power of the UE.
 27. The methodas claimed in claim 21, wherein the MAC-PDU further comprises a MAC-SDU.28. The method as claimed in claim 21, further comprising: transmittinga grant relating to scheduling an assignment of the uplink packet dataservice to the UE as scheduling results.
 29. The method as claimed inclaim 28, wherein the amount of data to be transmitted from eachpriority queues is determined with reference to a Transport FormatCombination (TFC) determined according to the grant.
 30. The method asclaimed in claim 21, wherein the priority queue is defined in accordancewith a kind of service.
 31. An apparatus for communication between aUser Equipment (UE) and a Node B in a communication system, theapparatus comprising: a reception unit for receiving a Media AccessControl-Protocol Data Unit (MAC-PDU) comprising scheduling informationhaving information representing an amount of packet data to betransmitted from the UE; a detection unit for detecting the schedulinginformation from the MAC-PDU; and a scheduler for scheduling an uplinkpacket data service of the UE based on the scheduling information,wherein the information representing the amount of packet data exist perpriority queue of the UE.
 32. The apparatus as claimed in claim 31,wherein the scheduling information is placed in the MAC-PDU before anyMAC Service Data Unit (SDU).
 33. The apparatus as claimed in claim 31,wherein, if a plurality of information representing the amount of packetdata exists in the scheduling information, the plurality of informationis arranged according to an order of priority queue ID.
 34. Theapparatus as claimed in claim 31, wherein the scheduling informationfurther comprises at least one information representing at least onepriority queue ID.
 35. The apparatus as claimed in claim 34, wherein theat least one priority queue ID is placed before any informationrepresenting the amount of packet data in the scheduling information.36. The apparatus as claimed in claim 31, wherein the schedulinginformation further comprises channel status information representing atransmission power of the UE.
 37. The apparatus as claimed in claim 31,wherein the MAC-PDU further comprises a MAC-SDU.
 38. The apparatus asclaimed in claim 31, wherein the scheduler transmits a grant relating toscheduling an assignment of the uplink packet data service to the UE asscheduling results.
 39. The apparatus as claimed in claim 38, whereinthe amount of data to be transmitted from each priority queues isdetermined with reference to a Transport Format Combination (TFC)determined according to the grant.
 40. The apparatus as claimed in claim31, wherein the priority queue is defined in accordance with a kind ofservice.